Silver halide color photographic light-sensitive materials (hereinafter also referred to as light-sensitive materials or photographic materials) are processed in developing, desilvering, washing, stabilizing and other processes after exposure. Silver halide black-and-white photographic light-sensitive materials are developed and fixed after exposure. A black-and-white developer or a color developer, a bleacher or a bleach-fixer, a fixer, tap water or deionized water, a stabilizing solution and a dye stabilizer are used for development, desilvering, fixing, washing, waterless washing and dye stabilization, respectively.
The liquids capable of performing these processes are called processing solutions. Each processing solution is usually kept at a temperature of 30.degree. to 40.degree. C., in which the light-sensitive material is immersed and processed.
These processes are usually carried out by sequentially transporting the light-sensitive material through processing tanks containing the above processing solutions, using an automatic processing machine or another means.
The automatic processing machine mentioned herein is generally a processing machine having a developing portion, a fixing portion, a desilvering portion, a washing or stabilizing portion and a drying portion, and a means for automatically sequentially transporting the photographic light-sensitive material to the processing tanks.
In carrying out processing using such an automatic processing machine, the processing solution in each processing tank is supplemented with a processing agent to keep the activity of the processing solution in the processing tank constant.
For this purpose, it is common to prepare a replenisher containing the processing agent dissolved therein.
Specifically, processing is carried out while supplying the previously prepared replenisher from the replenisher tank to the processing tank as appropriate.
In this case, it is the common practice to prepare the replenisher itself to be stored in the replenisher tank in a separate place, and in mini-labs etc., the replenisher is usually prepared in a given amount in a replenisher tank made within the processing machine at a time by manual dissolution or mixing dissolution using a mechanical mixer.
The silver halide photographic light-sensitive material processing agent (hereinafter also referred to as photographic processing agent) is supplied in the form of powder or liquid; it is prepared as a solution in a given amount of water in the case of powder. In the case of liquid, it is prepared as a dilution in a given amount of water in the case of liquid, since it is supplied in a concentrated state.
Replenisher tanks may be set by the automatic processing machine, requiring considerable space. Also, in recently-increasing mini-labs, replenisher tanks are housed in the automatic processing machine; in this case as well, sufficient space must be available for the replenisher tanks, each of which should contain at least 5 to 10 liter of replenisher.
Any processing agent for replenishment is divided in some parts to ensure constantly good performance in photographic processing. For example, the color developer replenisher is divided in three or four parts, and the bleach-fixer replenisher for color photography is divided in two parts: a part of the oxidant ferric salt of organic acid and a part of the reducing agent thiosulfate. In preparing the replenisher, said dense part of ferric salt of organic acid and said dense part of thiosulfate are mixed together and diluted with a given amount of water before using.
Said dense parts are placed in containers such as plastic containers, which containers are packed in outer packages, such as corrugated cardboard boxes, for 1 unit of commercial distribution.
The processing agent for replenishment in a kit of part agents is dissolved, diluted, mixed and then diluted to a given volume before using. Said processing agent for replenishment has the following drawbacks:
First, almost all conventional kits comprise dense aqueous solutions concentrated for improved operability, most of which are very dangerous because of high pH values of not more than 2.0 or not less than 12.0 in that they are harmful to the human body by skin contact etc. Also, many of them are strong oxidants or reducing agents, possessing very dangerous corrosivity in transport by ships or aircraft. The aqueous solution is subject to limitation as to solubility, being heavier and bulkier than in the case of solid. Since the concentrated solution is a dangerous article as stated above, its containers must be sufficiently tough to avoid destruction and spillage even if it is fallen; plastic container disposal poses a problem.
Second, the part agents are separately contained in respective containers; some processing agents for replenishment comprise several bottles of part agents so that each unit of commercial distribution thereof involves a considerable number of containers, which requires much space for storage and transportation. For example, the color developer replenishing agent for CPK-2-20QA, a processing solution for color printing paper, is available in 10-liter units, wherein part A (a kit including a preservative), part B (a kit including a color developing agent) and part C (alkaline agent) are each contained in a 500-ml plastic container. Similarly, the bleach-fixer replenisher is available in 8-liter units, wherein three part agents are contained in respective bottles. The stabilizer replenisher is available in 10-liter units, wherein two part agents are contained in respective bottles. These replenishing agents are stored and transported in respective outer packages of various sizes. The outer package size ranges from about 17.times.14.times.16.5 cm for the stabilizer replenisher to about 18.5.times.30.5.times.22.5 cm for the bleach-fixer replenisher; it is not possible to pile packages of replenishers in storing or transporting them or in stocking them at dealer shops unless they are of the same kind, so that much space is required.
The third drawback concerns with the problem of waste container disposal. In recent years, there has been strong demand for environmental conservation and saving resources mainly in Europe and the United States; in the photographic industry, plastic container disposal has been of major concern. Specifically, although plastic containers for photographic use are cheap, conveniently storable and transportable and excellent in chemical resistance, they pose problems of accumulation in the environment because they are hardly biodegradable, and emission of large amounts of carbon dioxide upon burning, which contribute to global warming and acid rain. As for the problems posed on the user side, they include decrease in the available working area due to occupation of the narrow working space by crowding plastic containers, which are too tough to compress.
The fourth drawback is poor chemical stability.
Usually, the life time of a replenisher is at most 2 weeks even in the presence of a floating lid. However, with the trend toward replenishing rate reduction, it has recently been often the case where a 10-liter replenisher is used over a period of more than 1 month in a mini-lab receiving an order of 30 rolls of color films daily on average.
In this case, the replenisher in the replenishing tank is often much more frequently in contact with air than the processing solution in the processing tank; often, replenishing has no effect due to replenisher deterioration. Accordingly, attempts have been made to reduce the replenishing tank capacity to 5 liter or reduce the replenishing kit unit to 5 liter. However, this approach involves another drawback of the necessity of additional packing material.
For example, in preparing a color developer replenisher for color printing paper, a given volume of water is placed in the replenisher tank, after which dense kit A, which contains a preservative, is added, followed by stirring, and dense kit B, which contains a color developing agent, is then added, followed by stirring, and dense kit C, which contains an alkaline agent, is then added, followed by stirring, and finally water is added to make a given volume. This series of procedures is liable to be accompanied by some problems. For example, in case of insufficient stirring or a failure to add the starting water, the color developing agent tends to crystalize, and the resulting crystal can stay in the bellows pump and fail to be supplied so that the photographic performance becomes labile or the bellows pump breaks. Also, the dense kits are not always used immediately after production; they may be used even 1 year after production; in some cases, performance becomes labile due to oxidation of the color developing agent or preservative.
The color developer replenisher prepared from dense kits or powder is also known to pose some problems in the replenisher tank. For example, if the replenisher remains unused for a long time, crystals can deposit on the inside wall of the replenisher tank, the replenisher becomes susceptible to oxidation, and tar forms. Under some storage conditions, other problems arise, including separation of easily-crystallizing components of the replenisher, such as the color developing agent, at low temperatures; some makers specify replenisher storage conditions and instruct the users to keep their replenishers under those conditions.
As stated above, when a replenisher, e.g., a color developer replenisher for color printing paper, is prepared using a commonly used dense kit or powder, the above-mentioned problems arise; similar problems arise in the case of bleach-fixer, bleacher and fixer. For example, the bleach-fixer is characterized by considerably poor storage stability. This is because the bleach-fixer is usually of high acidity and considerably low pH for neutralizing the alkalinity of the dye fixer carried over by the printing paper being processed because the bleach-fixing process immediately follows the process with a color developer of high pH. It is said that at low pH values, any bleach-fixer comprising a thiosulfate and an oxidant is considerably poor in storage stability and cannot be replenished at low replenishing rates. The same applies to the fixer and stabilizer.
Another problem is that the replenisher becomes increasingly dense in answer to the recent trend toward replenishing rate reduction and rapid processing; it has recently been a common practice to concentrate the replenisher to the limit of solubility.
This deteriorates replenisher storage stability, thus posing many practical problems such as crystal separation.
On the other hand, in addition to the above method of preparing a replenisher using a dense kit or powder, another method is known wherein a dense kit is added as such.
In this method, supplying means such as a bellows pump are used to supply the dense kit as such directly to the processing tank and a given volume of replenishing water is added independently, to improve the low efficiency in dissolving operation. This method really obviates solution preparing operation and is free of the problem of poor storage stability because no replenisher solution is prepared, in comparison with the above method, wherein the replenisher is prepared from a dense kit or powder.
However, this method also involves many problems. The major problem is the increased size of the automatic processing machine because of the necessity for a dense kit tank for supplying the dense kit and a pump for supplying the dense kit. For example, in the case of CPK-2-20, a processing solution for color printing paper, the dense kit of color developer replenisher is divided in three parts; the dense kit of bleach-fixer replenisher, three parts; and the dense kit of stabilizer replenisher, two parts. To supply all these dense kits, eight tanks and eight pumps are required. In the conventional replenishing method, three tanks and three pumps are sufficient, since each replenisher requires one tank and one pump. In short, more tanks and more pumps than in the conventional method are required for supplying the dense kits, and a pump for water used to prepare the replenisher is also required. Also, since bellows pump precision is not so high, it is difficult to accurately discharge a plurality of solutions simultaneously, which can result in an imbalanced composition.
Moreover, dense kits are difficult to maintain due to proneness to crystallization near the outlet of replenisher nozzle because they are dense solutions. Another problem is that the bellows pump is insufficient in supplying accuracy so that replenishing accuracy fluctuates widely in supplying a dense replenisher, resulting in very labile photographic performance. Still another problem is that the amount of waste plastic containers remains unchanged, in comparison with the conventional replenishing method, even when dense kits are supplied.
In addition to the above methods, some proposals have been made to obviate the use of plastic containers and improve replenisher chemical stability.
For example, Japanese Patent Publication Open to Public Inspection (hereinafter referred to as Japanese Patent O.P.I. Publication) No. 11032/1983 discloses an art wherein developing components are encapsuled in microcapsules; Japanese Patent O.P.I. Publication No. 61837/1976 discloses photographic tablets containing a disintegrating agent. Japanese Patent O.P.I. Publication Nos. 109042/1990, 109043/1990, 39735/1991 and 39739/1991 disclose methods using granular photographic processing agents having a particular average grain size.
The photographic tablets containing a disintegrating agent described in Japanese Patent O.P.I. Publication No. 61837/1976 are merely easily-soluble tablets. This proposal never leads to the idea of the present invention that a solid processing agent is added directly to the processing tank and dissolved therein.
Japanese Patent O.P.I. Publication No. 109042/1990 describes a granular photographic processing agent having a particular average grain size.
However, none of these publications proposes an automatic processing machine which has sufficiently simplified operability free of replenisher dissolving operation and which offers stable photographic performance or a compact automatic processing machine having no replenisher tanks.
On the other hand, as a means for obviating the necessity for previous dissolving operation, Japanese Patent O.P.I. Publication No. 11344/1991 discloses an art wherein pasty part agents, in amounts according to the mixing ratio of the part agents, are pushed out from respective unit containers and appropriately diluted at given dilution rates to accurately prepare and supply replenishers. Although this method really reduces or almost obviates the necessity for dissolving operation, pasty part agents are unstable because of the presence of solvent and are difficult to push out in given amounts for long periods, and in addition, when they are used at low frequencies, nozzle clogging tends to occur, which hampers the obtainment of constant photographic performance. Also, paste containers are required, which must be made of a flexible and tough material, usually a composite material, which is usually difficult to recycle and is hence undesirable from the viewpoint of environmental protection. Particularly, pasty chemicals are known to be poor in storage stability due to the use of organic solvent to prepare the paste.
Japanese Utility Model Publication No. 85732/1989 discloses an automatic processing machine having a means for adding a tablet fungicide to the stabilizer, but this never leads to the idea of a processing agent replenishment controlling means, since the fungicide itself poses no problem even in the event of entry in large amounts, and in addition, the addition of such a fungicide is essential, since its purpose is to preserve the stabilizer.
WO 91-07698 and WO 91-07699 disclose a method wherein CD-3 or CD-4 is added in a solid form while the other components added as activators in the form of liquid. However, the relevant patents concern with regeneration, particularly low rate replenishment involving almost no overflow, specifically a method wherein bromide and chloride ions are adsorbed and removed from the developer by means of ion exchange resin, after which the lacking components, namely alkali agent activator and a small amount of solid or liquid dense color developing agent are added while maintaining a constant volume.
The present invention is totally different from the inventions described above in that processing agent replenishment is achieved solely by adding a separately weighed solid processing agent to the processing tank and dissolve it therein, whereby previous replenisher dissolving operation is obviated to ensure maintenance-free operation; the present invention is never expected from the above invention.
A processing agent holding means that houses or affixes moisture-proof-packed processing agent packages, a numerical aperture of a processing tank that is 12 cm.sup.2 /l and control of replenishing water in an automatic processing machine employing solid processing agents, are not known.
In a conventional automatic processing machine, drive for a light-sensitive material transport means as well drive for a circulation pump for processing solutions and operation of a heater for a processing solution preparation tank have been stopped upon a termination of passing of a light-sensitive material, namely a termination of development processing. Accordingly, in an automatic processing machine employing solid processing agents such as tablets, in particular, a period of time from the moment of replenishment of solid processing agents to the moment when operations of the light-sensitive material transport means and the circulation pump are stopped after a termination of passing of a light-sensitive material, namely a termination of processing is short, and thereby circulation of solutions tends to be stopped with unsolved processing solutions remaining in a processing solution preparation tank and in a processing tank. In that case, extremely high concentration portions are caused in the processing solution preparation tank and processing tank during the suspended circulation, and when such high concentration portions are circulated again in processing for the following light-sensitive material, they give remarkable concentration unevenness to processing solutions, adversely affecting light-sensitive materials in terms of photographic characteristics. Or, when a developing agent of the processing solution is paraphenylenediamine used for a color developing agent, chemical change such as oxidation tends to be caused on processing agents at the high concentration portions, and thereby, substances which are hardly dissolved in the following circulation started again are produced, reducing effective concentration of the processing solution, which is a problem.